Studies are being carried out to: 1. determine mechanism of angiotensin induced contractions of smooth and cardiac muscle. 2. determine the properties of angiotensin receptors in adrenal cortex mediating aldosterone synthesis and release. BIBLIOGRAPHIC REFERENCES: Freer, R.J. and A.B. Smith. 1976. Effect of lithium on the responsiveness of rat uterine smooth muscle to angiotensin. Am. J. Physiol. 230:1132-1137. Freer, R.J., Pappano, A.J., Peach, M.J., Bing, K.T., McLean, M.J., Vogel, S. and N. Sperelakis. 1976. Mechanism for the positive inotropic effect of angiotensin II on isolated cardiac muscle. Circ. Res. 39:179-183.